#include <iostream>

using namespace std;

class Solution 
{
public:
    int mySqrt(int x) 
    {
        if (x < 1)
            return 0;
        int left = 1, right = x;
        while (left < right)
        {
            long long mid = left + (right - left + 1) / 2;
            if (mid * mid <= x)
            {
                left = mid;
            }
            else
                right = mid - 1;
        }
        return left;
    }
};
int main()
{
    int x = 8;
    Solution xz;
    int n = xz.mySqrt(x);
    cout << n << endl;

    return 0;
}